Pyrometer adapted to the control of temperature



Jan; 3, 1933. J. BRIDGES 1,893,134

PYROMETER ADAPTED To THE CONTROL OF TEMPERATURE Filed Feb. 5 1950 Inventor Fig-5 Q mes Bridges pe flttomW Patented Jan. 3, 1933 i i v i UNITED STATES Para-Mr rate 7 JAMES BRIDGES, or nonnon, ENGLAND, nssfenon T nnrunnro rnow Marinas COMPANY, oronroneo, ILLInoIs, A oonronnrron or ILLINOIS PYROMETER ADAPTED TO THE CON'IIt-Ol' 0F T EMfERA TURE Application filed February 3, 1930, Serial No. 425,612, and in Great Britain April 12, 1929.

his invention relates to temperature conin a horizontal plane over an inked marking trol apparatus of the type wherein mecharibbon located above a horizontal edge or nism, periodically operated by an auxiliary ridge over which'the chart runs. A deprespower, co-operate with the temperature resor bar locatedabove the index. and parallel' sponsive index of a pyrom'eter measuring a to the horizontal ridge is operated by a cam 1 temperature to be controlled, and-is adapted rotated by an auxiliary power, such as a to engage this index if it has moved beyond clock or electric motor, and is caused to fall a certain pointin response to the temperaperiodically so as toforce the index downture. passing beyond a certain value, such ward to cause the inked ribbon to mark the engagement etfeetingchange in the heating chart at the position of the intersection of B0 quantities supplied. The invention is parthe index and the horizontal ridge. Paralticularly applicable to recording pyrometers lel to the horizontal ridge, and on the same of the thermo-electric type and to other types ,level but nearer to the axis of the pyrometer I of recording pyrometers wherein the deflecmovement is located a flat support bar, tionof galvanometer provides a measure which is just touched by the index when it 65 of temperature, in which the index is noris forced fully down by the depressor bar. mally free to take up its position, according A frame, adapted to be periodically raised to the temperature, over=an inked marking and lowered by a cam, is located over the ribbon or thread which is located over the index and carries a carriage which may be record chart, but is periodically depressed adjustable spaced alongit in a direction by an auxiliary mechanism so as to mark parallel to the flatbar. The carriage carthe chart by forcing the marking ribbon into ri-es a pivoted tongue which extends obliquecontact therewith. In adapting such pyromly downward, and, when the pointeris not 'eters to the control of temperature it is thus in a position to be engaged, is adapted to necessary for the index tobe acted upon by just miss the inner edge of the supportbar two periodically operating mechanisms, onewhen the frame is moved downward. If, for the purpose of marking the chart and however, theindex is in a position to interonetor the purpose of temperature control. cept the tongue, the latter, owing to the As it is impracticable for both mechanisms oblique angle at which it stands, is moved 39 to be arranged to act on the index at the through an angle, the edge which contacts same pointit has not hitherto been possible the index sliding forward at the same time to secure proper support for the index to to a position over the support bar. Associresist the forces exerted by the action of both ated with the tongue are electrical contacts mechanisms and acouple is exerted on the for the control of the heating quantities,

35 index, tendingto damage the pivots of the the contacts being so adjusted .that they are 35 pyrometer movement. An object of the pres not forced into engagement until the edgeof ent invention is to provide means whereby thetongue has slid forward to the position a relatively large operating force may be over the support bar, so thatno-couple is exerted by the periodically operating mechaexerted on the index.

40 nism without exerting sucha couple on the In operation, at every cycle of operation, index. Another object of the invention is the depressor is first allowed to fall to mark to provide an improved mechanism for the the chart. The frame carrying the tongue control of temperature operating from a senis then lowered, and, if the index does not sitive temperature responsive index. intercept the tongue the electrical contacts The following description of a method of are not disturbed. If, however, the tempercarryingthe invention into effect is intended atu're condition is such that the index interonly as an example, and the invention is cepts the tongue, the latter is moved through here described as applied to a thermo-electric an angle and the electrical contact is recording pyrometer. changed, the index then being supported by The pyrometer index is arranged to swing the support bar at the point where it is engaged by the tongue.

which control is to be effected is set by movmechanism operated from theelectrical contacts.' In order that the preceding descript1o may be betterunderstood I will now proceedto describe the invention in relation to the accompanyingdrawing which shows, by way of example, the application of the invention p to a thermo-electric recording pyrometer.

In the drawing; Fig. 1 is a plan View of the apparatus. 7 Fig. 2 is an elevation of the said apparatus viewed in the direction of the arrow A.

Fig. 3 is an elevation of the'said apparatus viewed. in the direction of the arrow B.

Fig. 4is a detail. Fig. 5 is a diagram of connections.

The side plates 1 and 2 of' a recording pyrometer carry the usual record chart driving mechanism appertaining to" instruments of the type, but as such mechanisms-form no part of the present invention they have been omitted from the drawing. Over a horizontal knife edge 3 and in a plane parallel to the said knife edge, an index'or boom 4 of a temperature responsive element pivoted at 5, isnorinally free to move in response to ,the temperature to be controlled. An auxiliary power, such as a clockor an electric motor, drives a record chart 6, the chart passing from the roll7, over the knife edge 3 and the curved guide plate Sand thence'downward into a space'in which it accumulates. An inked marking ribbon 9 lies across the record chart above and parallel to the knife edge 3. Located above-the index 4 and parallel to the knife edgeis a I depressor bar 10 carried by the spindle 11 with bearings 12 and 13 in the side plates 1 and 2 respectively-"An extension .of the spindle 11 through the bearing 13 carries a follower 14 contacting with the periphery of a cam 15 carried by a spindle 16 rotated by the auxiliary power in the direction indicated by the arrow. The periphery of the cam 15 is shaped so as to allow the fol lower-14 and with it the depressor bar 10'to fall; under the action of gravity or of a spring, once during each'revolution of the said cam, thus periodically forcing the index 4 downward into contactwith the marking ribbon 9 causing the said ribbon to mark the record chart at the point of intersection of the index/1 and'the knife edge 3 and hold ing theindex in contact with the'ribbon' for an interval of time. Located above the depressor bar 10 and secured to a spindle 17 having bearings 18 and 19in the side plates 1 and 2 respectively is a frame comprising two side members 20 and 21- and a tie rodj22, the latter preferably The temperature at 21 carries at its lower end a roller 24 adapted I to contact with the periphery of a cam 25 also carried'by the spindle 16, the shape of the peripliery of the said cam being such as to allow the frame carried by the spindle 17 to slowly fall under the action ofgravity or of a spring once during each revolution of the said cam. Being'secured to the same spindle, the cams 15'and 25rotate at the same speed and in the same directionand they are so angnlarly p01 sltioned on the said spindle with respect to one another thatthe cam- 15 allows the depressor bar 10 to fall a short interval of time before the frame secured to the spindle 17 is allowed'to fall by the cam 25.

A threaded spindle 26 having bearings 27 and 28 in the sidemembers 20 and 21 respectively, carries a threaded nut 29 to which are attached two forked arms 30 and 31, the arms engaging and extending beyond the tie rod 2-2 to prevent rotation of said nut. 1A knurled knob 32'carried by an extension of the spindle 26through the bearing 28 provides means for rotating said spindle to axially'position carriage 33 separately illustrated by Fig.4

comprises a block 37 in which isa hole 38 of suitable size and shape, to permit axial movementof the block along the spindle 34,

without rotation thereon and a tongue-piece 39. secured to the said block which extends v, obliquely downward and which also has an upward extension forming an index registering with a suitable scale of temperature marked upon, a scale plate 40 located above and parallel to the spindle 3 1. A wire or other suitable stop 41 attached to the block 37, prevents the index 1, which moves inthe'direction from left to right as seen in Fig. 1 in response to an increase in the temperature to be controlled, from passing from under the tongue piece 39 in response to a rising temperature. Parallel to and with its upper face on the same level as the knife edge 3 but nearer to the axis 5 ofthe temperature responsive element is located a flat support bar 12, the position of said bar being such that when the frame secured to the spindle 17 falls, which takes place while the index 4 is held incontact with the ribbon 9 by the depressor bar 10, the leading edge of the tongue piece 39just misses and passes behind the inner edge of the bar 12, unless the said index is held in a position so as tointercept'the tongue, when the latter by reason of its obliquity is moved through an angle, partially rotating the spindle 34and at the same time iliding forward to a position over the support An arm 43 carried by an extension of the spindle 17 beyond the bearing 18 in the side plate 1 has secured to ita block 44 of insulati ing material such as ebonite, carrying contact arms 45 and 46 terminating in contacts 47 and 48 respectively. vThe spindle 34 extends beyond the bearing 35 in the side member 20 and terminates in a hub 49 of insulating material to which is attached a contact arm 50 carrying a contact 51 interposed between the contacts 47 and 48 and normally contacting with the top contact 47 under the action of a light coiled spring 52 or other suitable means.

An insulatingblock 53 secured to the side plate 2 carries resilient contact arms 54 and 55 terminating in contacts 56 and 57 respectively, the contacts normally being open but adapted to be closed by the pin 58 projecting from the face of the cam 15, a short interval of time after the frame carrying the spindle 34 and the carriage 33 is allowed to fall and held in contact untilthe rotation of the said cam carries the pin out'of contact with the arm 54 which occurs a short interval of time before the said frame is elevated, allowing the contacts 56 and 57 to open.

Suitable flexible connections 59 connect the contacts 47, 48 and 51 with insulated terminals 60 mounted on the side plate 1.

Fig. 5 shows how the contacts are connected with an electrical relay which controls the supply of heating medium, in which 61 is the relay operating coil, 62 a resistance to limit the current, 63 and 64 are pilot contacts and 65 and 66 contacts by the opening or closing of which the supply ofheating medium is respectively decreased or increased.

To describe the operation of the apparatus let it be supposed that the temperature to'be controlled is below the desired value and that the relay is not energizedfso that the quantity of heating medium supplied is insufficient to cause the temperature to rise to the desired 'value and insufficient also to maintain the temperature at thedesired value when the temperature is at this value. The index 4 assumes a position depending upon the temperature to be controlled. .Once during each V slowly descend and because the temperature is by supposition less than the desired value the index 4 does not intercept the tongue piece 39 which passes behind the support bar 42, the contacts 47 and 51 remaining closed under the action of the spring 52. The pin 58, rotating with the cam 15, closes the contacts 51 21116156, 57, and contacts 65 and 66 increasing the supply of heating medium. After an interval of time the rotation of the cam'carries the pin 58 out of contact with the contact arm 54 so that the contacts 56 and 57 open; but the relay remains energized by current flowing through contacts 63 and 64. The frame carrying the carriage 33'is raisedby the cam 25 as soon as the contacts 56 and 57 open and the depressor bar 10 is then raised by the cam 15 this completing one cycle of operation. This cycle of operation continues to be repeat-ed (but now the closing of contacts 56 and 57 during each cycle has no further efiect) until as a result of the increased supply of heating medium the temperature to be controlled increases until it reaches such a value that the index 4 moving in, response to the temperature intercepts the tongue piece 39 p when the frame carrying the carriage 33 is being lowered. When this occurs the edge of the tongue piece contacting with the index slides forward to a position over the support bar and in so doing rotates the spindle 34 in its bearings 35 and 36, transferring the contact 51 to the contact 48. Then when the" contacts 56 and 57 are closed by the pin 58,

the relay coil .61 is short circuited and the armature 16 released opening the contacts 63,

64 and 65, 66. The opening of the latter pair of contacts reduces the supply of heating medium. When the contacts 56 and 57 open in the manner previously described and the frame carrying the carriage 33 rises, the

spring 52 returns the contact 51 into contact with contact 47 but the relay is not thereby energized as the contacts 56 and 57 areopen.

The apparatus continues in operation without again operating the relay until the temperature falls below the desired value, when the apparatus operates to increase the supply of heating medium as has been previously described. The apparatus may be set to control the temperature at any value wlthln the 32 until the upward extension of the tongue piece forming an index registers with the desired temperature calibrated. on the scale plate 40. V r

Having now particularly described and ascertained the nature of my invention, and in what manner the same is to be performed,

'what I claim is:

1. In a control instrument, the combination with a condition sensitive indeX,-of an intermittently operating control member including a part dipping into the path of the index and adapted to be limited in its dipping movement When intercepted by the inrange of the apparatus by rotating the :knob

2. In a-control instrument, the combina tion with a condition sensitive index having a support for the forward end thereof, of a control member beatin 'acrossthe path of the index to the rear of the support and adapted to be limited by the index in certainpositionof the latter, and a second sup port, to the rear or the firstsupport, for the index when engaged by the member to carry the load of the member during its control operation. p V 3 In an electrical instrument, the combination of amovable pointer, a support for the anterior end of the pointer, a depressor bar pivoted to engage the pointer and hold the same against the support, a second support, a pivoted control mechanism includ ing' a part dipping across the path of the pointer in proximity to the second support andadaptedwhen intercepted by the pointer to move along the pointer until over saidsece ondsupport so that the pressure thereof is carried by said support and means for periodically actuating said depressor and controlmechanism. 7 v w I '4. In an electrical instrument, the combi nation of a pointer movable in a plane, two spaced apart supports above which the pointer freely swings, an intermittently operated depressor which presses the pointer against one of said supports, control means beat across the path of the pointer'adjacent the other support, said means including an element adapted to coactxwith the pointer in certain positions thereof thereby limiting movement ofsaid means, said element when contacting with thepointer adapted to move therea'long until over the support whereby the pressure of the means is exerted on the support and means for operating said depressor and control means.

Y 5. In an instrument of the type described, the combination of a movable member responsive to a condition, a support located closely adjacent to and parallel to the plane of movement of saie member, and an oscil lating means including a part beating across the plane of the lllClGX'ClOSQlY adjacent said support and adapted to coact with the index in certain positions thereof, said part adapted, when coasting with the index,'toride .therealong until co-incident with the support when its movement is arrested and the pressure exerted thereby is sustained by the support,

6. An instrument an index deflectable in a lane, a bar located closely adjacent to and parallel to said plane andan oscillatable control member including a finger movable into and out of theplane v of the index and inproximity to said bar and'adapted to coact with the index in oerhaving, in combination,

'7. An instrumenthaving, in combination, I

a movable index a su ort closely ad'ace'nt said index and aboye'which the index freely l moves,and an loscillatable control means including a part/pivoted thereon for, limited movement and dipp ng intothe path of the index, closely adjacent said support, said part I adapted to coact with the index in certain positions and when coacting therewith to ride therealong until above support, whereby the pressure exerted by the part in performing a control operation is carried by the support. I i I,

8. An instrument, having, in combination, movable indeiga frame, scale plate car- -'ied thereby, a support bar carried by said rame'and located closely adjacent. to said index but normally out of contact therewith, an oscillatable means mounted in said frame and a lever pivotallysupport ,d o'n said means so that one end thereof cooperates with said scale to indicate the position'thereof and the other end dips across the path or" theindex and coacts' therewith in certain positions thereof to limit movement of said means, said end oft-the lever, when coacting with the indeX, sliding'therealong until opposite said bar, whereuponthe other end thereof contacts with said scale to limit further movement along the index and the pressure exerted thereby is carried by the support.

JAMES BRIDGES. 

